F = m A
Divide each side by acceleration, and then the equation says:
Mass = force/acceleration
m1 = 5N / 5m/s^2 = 1 kg
m2 = 10N/10m/s^2 = 1 kg
If you glue them together, you have a single object with 2kg of mass.
Its acceleration is (force)/2 m/s^2 .
